Studies of cockroach allergy have expanded to include studies of extracts prepared for single sexes of roaches, as well as different strains of roaches. Samples have also been analyzed from the crop, mid and hind gut of roaches, and the effect of various changes in rearing methods is under investigation. Acquisition of an allergic serum pool has been delayed, although the initiation of contact with pesticide manufacturers may provide additional sources of serum for analysis.